Quality evaluation method, information recording medium, optical disc device and recording/reproducing system

An optical disc device, comprising:

• an optical pickup unit having an optical system that irradiates a recording medium with a light from a light source;
• a unit that generates the recorded waveform of the light irradiation for recording user data on the recording medium;
• a signal processing unit that processes a reading signal from the optical pickup unit;
• and
• a particular pattern signal generation unit that determines a recorded waveform of a particular pattern having a lifetime shorter than a reference lifetime of the user data.

A recording/reproducing system, comprising:

• a recording medium on which a particular pattern having a lifetime shorter than a reference lifetime of user data is recorded;
• an optical pickup unit having an optical system for irradiating the recording medium with a light from a light source;
• a unit that generates the recorded waveform of the light irradiation for recording the user data;
• a quality evaluation unit that conducts quality evaluation on a reading signal output from the optical pickup unit;
• and
• a timing control unit that gives an instruction on a timing of the quality evaluation.